The invention relates to elements formed of a composition of glass fibers and reinforcing polymeric resin, and expanded or cellular polymeric foam or felt.
It is well known to use compositions of polymeric resins, with or without glass fibers, for forming structural elements and, in particular, non-load bearing structural elements, for replacing heavier or more expensive materials. However, in certain environments, e.g., within the passenger compartments of modern aircraft, such composites are often unable to meet stringent requirements of strength and performance established for the safety of those within that environment. These requirements may be particularly strict where there is a perceived danger of fire. It is well-known that the performance of certain polymeric-based materials may be unsatisfactory, or even life-threatening, for reasons of heat release, flammability, smoke release and/or toxic gas release, and also for lack of strength, impact resistance and compression resistance, making these materials unsuitable for use in environments where they might otherwise provide a substantial benefit. A prohibitively high level of heat release, flammability and smoke and/or toxic gas release can be reduced by adding fire retardants to the polymeric resins.
In certain environments, the composite may transmit an undesirable level of heat and/or sound.